JP2006242490A - Stoker-type incinerator and its operation method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a stoker-type incinerator capable of simultaneously realizing effect of reducing unburned matters and heavy metals in incineration main ash, effect of reducing ash dust such as soot, unburned carbon and ash carried with a combustion gas, and effect of reducing NOx by promoting the combustion in a combustion zone of the furnace and inhibiting generation of NOx caused by recirculation of a recirculated gas with good balance, in the stoker type incinerator comprising a recirculation passage for allowing a part of a combustion exhaust gas in a combustion chamber to be recirculated into the furnace as the recirculated gas. <P>SOLUTION: In this stoker-type incinerator 2 wherein the primary air is introduced from lower parts of stokers 21-23 in which a burned object is charged to implement primary combustion by the primary air in the combustion chamber 3 at an upper part of the stokers, and then the secondary air is charged to an upper part of the combustion chamber 3 to implement secondary combustion, the combustion exhaust gas in the combustion chamber 3 is partially recirculated to the furnace as the recirculated gas, and oxygen in the primary air is enriched to control oxygen concentration of the primary air supplied to the main combustion zones 21-23 at the upper part of the stokers, within a range of 21-40% to implement combustion in the main combustion zone. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention introduces primary air from below a stalker into which combustibles such as waste and industrial waste are charged, performs primary combustion with the primary air in the combustion chamber above the stalker, The present invention relates to a stoker-type incinerator and a method for operating the stoker-type incinerator so as to perform secondary combustion by introducing secondary air into an upper portion.

  The stoker-type incinerator is equipped with a stalker in which fixed-stage and movable-stage grates are alternately arranged, and the movable stage is reciprocated by a hydraulic device to agitate the waste (burned material) introduced from the hopper. While moving forward, the waste is dried in the drying zone located upstream of the stoker, and the main combustion is performed while introducing primary air in the next main combustion zone, and burns in the most downstream combustion zone. An incinerator configured to perform combustion every remaining portion.

  In such a stoker type incinerator, the recirculated gas extracted from a part of the combustion exhaust gas in the combustion chamber above the stoker is recirculated to the secondary combustion section in the combustion chamber through the recirculation passage and combusted with the secondary air. A technique provided is provided (for example, see Patent Document 1).

In the technique provided in Patent Document 1, a part of the flue gas in the combustion chamber above the stoker is extracted and sent to the heat exchanger as a recirculation gas. In the heat exchanger, the recirculation gas primary air and The primary air and the secondary air are preheated by exchanging heat with the secondary air, and the recirculated gas is upstream of the secondary air supply port in the combustion chamber by a fan disposed on the downstream side of the heat exchanger. In the side part, the atmosphere upstream from the secondary air supply port is made a weakly reducing atmosphere, the total air ratio in the combustion chamber after supplying the secondary air is suppressed to about 1.3, and the unburned gas NOx is reduced while completely burning unburned materials.
Japanese Patent No. 3558210

However, the above-described conventional stoker-type incinerator and its operating method have the following problems.
That is, in the prior art, after extracting a part of the combustion exhaust gas in the combustion chamber above the stoker and preheating the primary air and secondary air as recirculation gas, the recirculation gas is supplied to the secondary air supply port in the combustion chamber. In addition, the self-denitration region is formed by suppressing the generation of NOx by making the atmosphere upstream of the secondary air supply port into a weakly reducing atmosphere and forming a self-denitration region. For this reason, the above-mentioned prior art is to put the recirculation gas into the upstream side part of the secondary air supply port in the combustion chamber and to suppress the generation of NOx by making this part a reducing atmosphere. The prior art does not disclose a technical idea that combines the reduction of NOx by recirculation gas with the reduction of unburned main ash, heavy metals, etc. in the incinerated main ash by promoting combustion in the combustion zone of the stoker furnace.
Therefore, in the prior art, the effect of reducing unburned components and heavy metals in the incinerated main ash and the effect of reducing soot, unburned carbon, ash and other soot accompanying the combustion gas cannot be expected.

  The present invention has been made in view of such a situation, and an object thereof is a stoker type incinerator having a recirculation passage for recirculating a part of combustion exhaust gas in a combustion chamber as recirculation gas into the furnace. By achieving a good balance between combustion promotion in the combustion zone of the furnace and suppression of NOx generation by recirculation of the recirculated gas, the effect of reducing unburned combustibles, heavy metals, etc. in the incinerated main ash and accompanying the combustion gas It is an object of the present invention to provide a stoker-type incinerator capable of realizing both the soot, unburned carbon, dust reduction effects such as ash, and the NOx reduction effect, and an operating method thereof.

In order to solve the problems of the prior art, the present invention introduces primary air from below the stoker where the combusted material is burned, and after performing primary combustion with the primary air in the combustion chamber above the stoker, In the operation method of the stoker type incinerator in which a part of the combustion exhaust gas generated in the combustion chamber is recirculated into the furnace as a part or all of the secondary air, the main combustion zone above the stoker in the primary air Is enriched so that the oxygen concentration of the primary air supplied to the range of 21% to 40% is burned in the main combustion zone.
In the above invention, it is preferable that the exhaust gas after the secondary combustion is introduced in one or more stages upstream of the secondary air or / and the recirculated gas in the combustion chamber.

Further, the invention of the apparatus for carrying out the operation method is characterized in that primary air is introduced through a primary air supply passage from below a stalker in which combustibles are incinerated, and primary combustion is performed by the primary air in a combustion chamber above the stalker. In the operating method of the stoker-type incinerator for recirculating a part of the combustion exhaust gas generated in the combustion chamber into the furnace as a part of the secondary air or as a whole, in the primary air supply passage, The enrichment oxygen supply passage for supplying oxygen for enrichment of the primary air is connected to the primary air supply passage to the main combustion zone above the stoker, and the oxygen concentration of the primary air to the main combustion zone Is provided with an oxygen concentration adjusting device for adjusting the amount of oxygen in the enrichment oxygen supply passage so that the oxygen concentration range is 21% to 40%.
Furthermore, the invention of the apparatus for carrying out the operation method includes a primary air supply passage through which primary air is introduced from below a stalker in which combustibles are incinerated, and combustion in which primary combustion is performed by the primary air above the stalker. And a stoker-type incinerator operating method in which a part of the flue gas generated in the combustion chamber is partly or entirely recirculated into the furnace as oxygen in the primary air supply passage. And an oxygen concentration adjusting device for adjusting the oxygen amount in the enrichment oxygen supply passage so that the oxygen concentration of the primary air to the main combustion zone is in the oxygen concentration range of 21% to 40%. I have.
In the present invention, it is preferable that an EGR gas blowing nozzle for supplying combustion exhaust gas after secondary combustion is provided in the combustion chamber.
In the present invention, it is preferable that the EGR gas blowing nozzle is provided upstream of the secondary air nozzle and / or the recirculation gas nozzle.
Further, in the present invention, it is preferable that the EGR gas blow-out nozzle inputs combustion exhaust gas after secondary combustion over one stage or a plurality of stages.
And in the said invention, it is preferable to provide the circulation means which circulates the fly ash produced | generated after the said secondary combustion to the said stoker directly or after washing | cleaning.
Further, in the present invention, classification means for classifying main ash generated after burning in the stoker into small particle ash having a predetermined particle size or less and large particle ash exceeding the certain particle size, and the small particles Circulating means for circulating the diameter ash through the stoker and burning it on the stoker is preferably provided.

The present invention also includes the following two operating methods in addition to the operating method of the stoker type incinerator.
(1) A driving method in which fly ash generated after secondary combustion is directly or after washing, circulated to the stalker and burned on the stalker.
(2) The main ash produced after burning in the stoker is classified into a small particle ash having a particle size equal to or smaller than a certain particle size and a large particle ash exceeding the certain particle size, and the small particle ash is circulated to the stoker. And an operation method for burning on the stoker.

  According to the present invention, a part of the combustion exhaust gas extracted from the combustion chamber above the stoker is recirculated as a recirculation gas, preferably in one or more stages in the upstream portion of the secondary air, Oxygen is added to the primary air supplied to the main combustion zone, which is the main combustion zone of the stoker, among the dry zone, the main combustion zone, and the vertical combustion zone of the stoker, so that the oxygen concentration in the main combustion zone is higher than the normal oxygen concentration. Since the main combustion in the main combustion zone is performed while maintaining the oxygen enriched range of 21% to 40%, the combustion temperature rises due to the combustion in the oxygen enriched state in the main combustion zone.

Due to such rise in combustion temperature, fuel supply fluctuations and quality fluctuations, and combustion exhaust gas characteristics fluctuations due to uncertainty in the transfer rate of combustibles (garbage) above the stoker can cause poor combustion in the main combustion zone. Generation can be prevented, and generation of soot such as soot, unburned carbon and ash accompanying the combustion gas can be prevented.
In addition, the oxygen enrichment also increases the temperature of the ash layer after combustion in the main combustion zone and after combustion in the vertical combustion zone, so that unburned components in the incinerated main ash, unburned components such as heavy metals can be reduced. Therefore, a melting facility for melting such unburned components is unnecessary, and the properties of the incinerated main ash can be improved.

Further, a part of the combustion exhaust gas burned at a high temperature as described above is extracted from the combustion chamber above the stoker together with oxygen that has risen into the combustion chamber without being used for the combustion, and this recirculated gas is extracted from the combustion chamber. Preferably, by introducing one or more stages upstream of the secondary air or / and the recirculated gas, the reduction atmosphere of the secondary air upstream part in the combustion chamber is promoted, It is possible to suppress an increase in the generation of NOx due to high-temperature combustion in an oxygen-enriched state.
In addition, the combustion exhaust gas discharged from the incinerator, passed through a temperature-decreasing tower and a bag filter, subjected to temperature reduction, dust removal, and acid gas neutralization step, is disposed in one stage upstream of the recirculation gas in the combustion chamber. By introducing it over a plurality of stages, it is possible to promote the reduction atmosphere of the secondary air upstream portion in the combustion chamber, and to suppress the increase in the generation of NOx due to the high-temperature combustion in the oxygen-enriched state as described above.
Therefore, according to the present invention, by promoting the combustion in the combustion zone above the stoker and suppressing the generation of NOx by the recirculation of the recirculated gas in a well-balanced manner, the effect of reducing unburned components, heavy metals, etc. in the incinerated main ash In addition, a stoker-type incinerator that can achieve both the soot, unburned carbon, ash and other dust reduction effects accompanying the combustion gas and the NOx reduction effect can be obtained.

Further, according to the present invention, the fly ash discharged through the secondary combustion and containing a relatively large amount of harmful substances such as dioxins is directly or after washing, circulated to the stoker and burned on the stoker. As described above, the amount of dioxin discharged from the incinerator is remarkably reduced by allowing the fly ash to stay in a furnace where high temperature combustion is performed by oxygen enrichment as described above for a long time and then discharging it as combustion main ash. it can. Further, since salts and heavy metals contained in the fly ash are extracted from the fly ash, the salts and heavy metals in the combustion main ash are reduced, and the roadbed material, concrete aggregate, and cement raw material are used without using a melting furnace. It can be turned into resources.
Further, according to the present invention, the main ash produced after the combustion in the stoker is classified into a small particle ash having a predetermined particle size or less and containing heavy metals and a large particle ash exceeding the certain particle size. In addition, the small particle size ash can be reburned to reliably remove the unburned components in the main ash, and the large particle size ash can be discharged as it is to a harmless state that can be treated. This is because it is known that the incinerated main ash contains a relatively large amount of substances that cause environmental pollution such as heavy metals in a small particle size.

[First Embodiment]
FIG. 1 is a configuration diagram of a stoker-type incinerator according to the first embodiment of the present invention.
In FIG. 1, 1 is a garbage hopper into which combustibles such as garbage and industrial waste are charged, and 2 is a stoker type incinerator. This stoker type incinerator 2 mainly comprises a dry zone stoker 21 that mainly constitutes a dry zone, a main combustion zone stoker 22 that mainly constitutes a combustion zone, and a main combustion zone that is mainly formed at the bottom of the furnace at the inlet from the waste hopper 1. In addition, a combustion zone stoker 23 is laid. The dry zone stalker 21 is located on the most upstream side, the main combustion zone stalker 22 is located on the downstream side of the dry zone stalker 21, and the vertical combustion zone stalker 23 is located on the most downstream side downstream of the main combustion zone stalker 22. Yes. Here, the main combustion zone refers to an area where a flame is raised on the dust layer and burned.
Each of the stokers 21, 22, and 23 is provided with a moving grate disposed between fixed grate, and after putting in garbage (combustible material) by reciprocating movement of the moving grate, the garbage is put in the stoker 21. After drying, the main combustion is performed by the stalker 22, and finally the combustion is performed by the stalker 23. In this embodiment, the number of combustion zone stokers 22 is three, but it is sufficient that one or a plurality of combustion zone stokers 22 are provided. 8 is an ash collection tank.
A primary combustion chamber 3 is provided above the stokers 21, 22, and 23, and a secondary combustion chamber 4 is provided above the primary combustion chamber 3.

  The dry zone stalker 21, main combustion zone stalker 22 and vertical combustion zone stalker 23 are provided with primary air pipes 51, 52 (three), 53 that open to the lower wind boxes, respectively. Primary air is supplied. 6 is a primary air supply fan, 5 is a primary air main pipe that connects the fan 6 and each of the primary air pipes 51, 52 (three), 53, and the primary air pumped from the fan 6 is primary air. The main pipe 5 is distributed to the primary air pipes 51, 52, 53. Therefore, the primary air supply passage is constituted by the primary air pipes 51, 52, 53 and the primary air main pipe 5. In the primary air pipes 51, 52, 53, on-off valves 54, 55, 56 are provided for opening / closing them, and in the primary air main pipe 5, an on-off valve 7 for opening / closing them is provided. .

  81 is a boiler connected to the exhaust gas outlet of the secondary combustion chamber 4, 8 is a temperature reduction tower, 9 is a bag filter (dustproof device), and is discharged from the outlet of the secondary combustion chamber 4 of the stoker type incinerator 2. Exhaust gas is generated by steam from the feed water by the boiler 81, then cooled by the temperature reducing tower 8, and after fly ash and the like are removed by the bag filter (dustproof device) 9, it is discharged from the chimney 10 into the outside air. It is like that.

EGR gas blowing nozzles 20 a and 20 b are installed on the inlet side of the secondary combustion chamber 4. The EGR gas blowing nozzles 20 a and 20 b are supplied with exhaust gas that has passed through a bag filter (dustproof device) 9.
That is, the EGR gas is supplied from the EGR passage 30 through the EGR passages 31 and 32 by the EGR fan 11 and is jetted into the secondary combustion chamber 4 from the EGR gas blowing nozzles 20a and 20b.
The EGR gas may be exhaust gas discharged from an incinerator and subjected to temperature reduction, dust removal, and acid gas neutralization through a temperature reducing tower and a bag filter. Reference numerals 25a and 25b denote secondary air blowing nozzles for blowing secondary air into the secondary combustion chamber 4 from downstream portions of recirculation gas blowing nozzles 19a and 19b described later.

Reference numeral 40 denotes a recirculation gas extraction port for extracting a part of the combustion exhaust gas in the primary combustion chamber 3 (or in the secondary combustion chamber 4) as recirculation gas, and the recirculation gas extraction port 40 extracted from the recirculation gas extraction port 40 Circulating gas is introduced into the inlet 14 of the cyclone 12 through the recirculation passage 16.
Then, the recirculated gas removed by the known means in the cyclone 12 passes through the recirculation passage 15 by the recirculation fan 13 and is installed in the upstream portion of the secondary air blowing nozzles 25a and 25b in the secondary combustion chamber 4. The recirculation gas blowing nozzles 19a and 19b are fed into the secondary combustion chamber 4 from the recirculation gas blowing nozzles 19a and 19b. Note that the recirculation gas blowing nozzles 19a and 19b may be provided in a plurality of stages in the secondary combustion chamber 4 along the gas flow.

26 is an oxygen supply device, and 28 is an oxygen supply passage for enrichment that connects the oxygen supply device 26 and the primary air pipe 52 to the main combustion zone stoker (three in this example) 22. The oxygen thus supplied is introduced into the primary air pipe 52 to the main combustion zone stalker 22 through the enrichment oxygen supply passage 28.
29 is an oxygen concentration control valve that changes the passage area of each enrichment oxygen supply passage 28, and 27 is an oxygen concentration adjusting device that controls the opening of each oxygen concentration control valve 29.
As will be described later, the oxygen concentration adjusting device 27 controls the opening degree of each oxygen concentration control valve 29 so that the oxygen concentration of the primary air to the main combustion zone stalker 22 falls within the oxygen concentration range of 21% to 40%. Configured to control.

That is, in the oxygen concentration adjusting device 27, the relationship between the oxygen concentration in the primary air to each main combustion zone stoker (three in this example) 22 and the opening degree of each oxygen concentration control valve 29 is set. The oxygen concentration is in a range of 21% to 40% that is oxygen-enriched than the normal oxygen concentration, and primary oxygen-enriched air is sent to each main combustion zone stalker 22. If the oxygen concentration is maintained within the range of 21% to 40% enriched with oxygen, combustion promotion by increasing the combustion temperature and suppression of NOx generation by recirculation of recirculated gas are performed on the main combustion zone stoker 22 in a well-balanced manner. It becomes possible.
According to the experiments conducted by the inventors, the optimum oxygen concentration for each main combustion zone stalker 22 is 21 to 35% in the main combustion zone stoker on the most upstream side (the waste hopper 1 side), and the main combustion zone in the next stage. The stoker is 21 to 40%, and the main combustion zone stoker on the most downstream side (the ash collection tank 8 side) is 21 to 40%.

  In the stoker-type incinerator 2 and the operation method thereof according to the first embodiment of the present invention, a part of the combustion exhaust gas extracted from the combustion chamber (primary combustion chamber 3 or secondary combustion chamber 4) above the stoker is recycled gas. In the combustion chamber, one stage or a plurality of stages are introduced upstream of the secondary air blowing nozzles 25a and 25b, and the stoker drying zone 21, the main combustion zone stoker 22, and the vertical combustion zone stoker 23 Of these, oxygen is added to the primary air supplied to the main combustion zone stalker 22 which is the main combustion zone of the stalker, and the oxygen concentration in the main combustion zone stalker 22 is increased from 21% to the oxygen concentration higher than the normal oxygen concentration. Since the main combustion is performed on the main combustion zone stalker 22 while maintaining the range of 40%, the combustion temperature is increased by combustion in the oxygen-enriched state on the main combustion zone stalker 22. It will be rising.

Therefore, according to the stoker-type incinerator 2 and the operation method thereof according to the first embodiment of the present invention, due to the increase in the combustion temperature, fuel supply fluctuations and quality fluctuations, and combustibles (garbage) above the stoker It is possible to prevent the occurrence of poor combustion on the main combustion zone stoker 22 due to fluctuations in the flue gas properties caused by the uncertainty of the transfer speed, and to generate soot, unburned carbon, ash, etc. accompanying the combustion gas Can be prevented.
Further, the oxygen enrichment as described above also increases the temperature of the ash layer after combustion on the main combustion zone stoker 22 and combustion on the vertical combustion zone stoker 23, so that the unburned content in the incinerated main ash, Unburned components such as heavy metals can be reduced, and a melting facility for melting such unburned components is not required, and the properties of the incinerated main ash can be improved.

Then, a part of the flue gas burned at a high temperature as described above is not supplied to the combustion, but is brought into the primary combustion chamber 3 and the secondary combustion chamber 4 together with the primary combustion chamber 3 or the secondary combustion. By extracting the recirculated gas from the chamber 4 and supplying it in one or more stages upstream of the secondary air blowing nozzles 25a, 25b in the secondary combustion chamber 4, the inside of the secondary combustion chamber 4 The secondary air blowing nozzles 25a and 25b can be promoted to form a reducing atmosphere, and an increase in the generation of NOx due to high-temperature combustion in the oxygen-enriched state as described above can be suppressed. This effect becomes more stable by using the combustion exhaust gas supplied from the EGR gas blowing nozzles 20a and 20b.
By the above, it becomes possible to perform well-balanced promotion of combustion on the main combustion zone stalker 22 and suppression of NOx generation by recirculation of the recirculated gas, thereby reducing the unburned content and heavy metals in the incinerated main ash. And the stoker type incinerator which can implement | achieve the reduction effect of soot accompanying uncombusted carbon, ash, etc. accompanying combustion gas, and the reduction effect of NOx can be obtained.

[Second Embodiment]
FIG. 2 is a configuration diagram of a stoker-type incinerator according to the second embodiment of the present invention.
In the second embodiment, solid content processing means is added to the configuration of the first embodiment.
That is, in FIG. 2, reference numeral 62 denotes a fly ash washing / dissolving means, which dissolves the fly ash from the bag filter (dustproof device) 9 by mixing water. The fly ash dissolved in the dissolving means 62 is dehydrated by the dehydrating means 63 to become a solid content from which water has been separated, and is put into the waste hopper 1 through the fly ash reflux line 65, and is stoker-type with the garbage. It is configured to burn in the incinerator 2.
Therefore, according to the second embodiment of the present invention, the fly ash generated after the secondary combustion in the secondary combustion chamber 4 and containing a large amount of dioxin is circulated to the stoker type incinerator 2 so as to be placed on the stokers 21, 22, 23. By making the fly ash stay in a furnace where high temperature combustion is performed by oxygen enrichment as in the first embodiment for a long time, and then discharging as combustion main ash, the stoker type incinerator The amount of dioxins discharged from 2 can be significantly reduced.

Moreover, in FIG. 2, 60 is a classification means, and this classification means 60 makes the main ash stored in the ash collection tank 8 less than a certain particle diameter after the final combustion in the above-mentioned combustion zone stoker 23. The ash is classified into a small particle size ash and a large particle size ash exceeding the certain particle size.
The large particle size ash is pulverized by a coarse pulverizing means 61 having a classification function, and the small particle size ash is introduced into the garbage hopper 1 through a main ash reflux line 64 and burned together with the garbage in the stoker incinerator 2. Will be. On the other hand, of the ash pulverized by the coarse pulverizing means 61, the large particle ash exceeding a certain particle size is discharged as it is and reused as roadbed material, concrete aggregate or the like. Further, the small particle size ash having a predetermined particle size or less merges with the small particle size ash from the classification means 60 and is put into the garbage hopper 1.
Thus, according to the second embodiment of the present invention, the main ash produced after the combustion in the stoker-type incinerator 2 has a small particle size ash that is less than a certain particle size and contains heavy metals and the like and the certain particle size. The ash can be classified into a large particle size ash that exceeds the minimum particle size ash, and the small particle size ash can be reburned to ensure the removal of unburned components in the main ash. Can be in a state.
Other configurations are the same as those of the first embodiment, and the same members are denoted by the same reference numerals and description thereof is omitted.

While the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and various modifications and changes can be made based on the technical idea of the present invention.
For example, a part of the primary air pumped from the fan 6 can be introduced into the recirculation gas exiting from the cyclone 12 so that the oxygen concentration of the recirculation gas returning to the furnace can be adjusted.

It is a lineblock diagram of the stoker type incinerator concerning a 1st embodiment of the present invention. It is a block diagram of the stoker type incinerator which concerns on 2nd Embodiment of this invention.

Explanation of symbols

1 Waste Hopper 2 Stoker Incinerator 3 Primary Combustion Chamber 4 Secondary Combustion Chamber 9 Bag Filter (Dustproof Device)
12 Cyclone 19a, 19b Recirculation gas blowing nozzle 20a, 20b EGR gas blowing nozzle 21 Dry zone stalker 22 Main combustion zone stalker 23 Alternate combustion zone stalker 25a, 25b Secondary air blowing nozzle 26 Oxygen supply device 27 Oxygen concentration adjustment device 28 Rich Oxygen supply passage 29 Oxygen concentration control valve 40 Recirculation gas outlet 51, 52, 53 Primary air pipe 60 Classification means 61 Coarse grinding means 62 Dissolution means 63 Dehydration means

Claims (11)

After introducing primary air from below the stoker where the combustibles are burned, and performing primary combustion with the primary air in the combustion chamber above the stoker, a part of the combustion exhaust gas generated in the combustion chamber is secondary air In a method of operating a stoker-type incinerator that recirculates into the furnace as a part or all of
Of the primary air, the oxygen concentration of the primary air supplied to the main combustion zone above the stoker is enriched with oxygen so as to be in the range of 21% to 40%, and burned in the main combustion zone. How to operate a stoker incinerator.   2. The stoker type incinerator according to claim 1, wherein the exhaust gas after the secondary combustion is introduced into the upstream portion of the secondary air or / and the recirculated gas in one or more stages. Driving method.   3. The stoker-type incinerator according to claim 1, wherein the fly ash generated after the secondary combustion is directly or after cleaning, is circulated to the stoker and burned on the stoker. how to drive.   The main ash produced after burning in the stoker is classified into a small particle ash having a predetermined particle size or less and a large particle ash exceeding the certain particle size, and the small particle ash is circulated through the stoker to circulate the ash. The method for operating a stoker-type incinerator according to any one of claims 1 to 3, wherein combustion is performed on a stalker. After introducing primary air through the primary air supply passage from below the stoker where the combustibles are incinerated, and performing primary combustion with the primary air in the combustion chamber above the stoker, the combustion exhaust gas generated in the combustion chamber In the operation method of the stoker type incinerator in which the part is recirculated into the furnace as part or all of the secondary air,
An enrichment oxygen supply passage for supplying oxygen for enrichment of the primary air is connected to a primary air supply passage to a main combustion zone on the stoker among the primary air supply passages, and the main combustion A stoker-type incineration comprising an oxygen concentration adjusting device for adjusting the amount of oxygen in the enrichment oxygen supply passage so that the oxygen concentration of the primary air to the belt is in an oxygen concentration range of 21% to 40% Furnace. A primary air supply passage for introducing primary air from below the stoker where the combustible is incinerated, a combustion chamber for performing primary combustion with the primary air above the stoker, and a part of the combustion exhaust gas generated in the combustion chamber In the operation method of the stoker type incinerator that recirculates into the furnace as a part or all of the secondary air,
An oxygen supply device for supplying oxygen for enrichment to the primary air supply passage, and an oxygen supply passage for enrichment so that the oxygen concentration of the primary air to the main combustion zone is in an oxygen concentration range of 21% to 40%. A stoker-type incinerator comprising an oxygen concentration adjusting device for adjusting the amount of oxygen. The stoker type incinerator according to any one of claims 5 to 6, wherein an EGR gas blowing nozzle for supplying combustion exhaust gas after secondary combustion is provided in the combustion chamber.   The stoker-type incinerator according to any one of claims 6 to 7, wherein the EGR gas blowing nozzle is provided at a position upstream of the secondary air nozzle and / or the recirculation gas nozzle.   The stoker type incinerator according to any one of claims 6 to 8, wherein the EGR gas blowing nozzle inputs combustion exhaust gas after secondary combustion over one stage or a plurality of stages.   The stoker type incinerator according to any one of claims 6 to 9, further comprising circulation means for circulating fly ash generated after the secondary combustion directly or after washing to the stoker.   Classifying means for classifying the main ash produced after the combustion in the stoker into a small particle ash having a particle size equal to or smaller than a certain particle size and a large particle ash exceeding the certain particle size, and circulating the small particle ash to the stoker The stoker type incinerator according to claim 10, further comprising circulation means for burning on the stoker.

Images